Hot air and infrared heating methods as alternative control methods against Tribolium castaneum (Herbst.) and their effect on the physiochemical properties of finger millet (Eleusine corocana) flour

Abstract

Excessive use of synthetic insecticides has raised widespread environmental concerns. Synthetic fumigants such as methyl bromide and phosphine pose significant hazards causing severe environmental issues like ozone depletion, pollution toxicity to non-target organisms, pesticide residues and non-biodegradable properties. The study aims to employ alternate methods for chemical fumigants to disinfest stored pest, T. castaneum in finger millet flour using Hot air (HA) and Infrared (IR) heating methods. HA treatment at 65 $°C$ for 10 min and IR heating at 1760 W for 9 min resulted in 100% mortality of all the life stages of the pest. The mortality (LT₅₀ and LT₉₉) was determined using probit analysis and the mortality data was subjected to generate a regression equation. Considering the properties of the treated flour, HA showed slight increase in bulk density as the temperature and time increased and IR exhibited significant effect on bulk density, influencing the flowability and compressibility of the flour. SEM images on the surface of HA treated flour was smooth, and IR treated flour with surface irregularities were noticed and the surface of untreated flour was coarse. HA and IR can be used for the disinfestation of millet flour thus maintaining the product quality. This research provides valuable insights for sustainable pest management and environment sustainability.